{
 "cells": [
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "# SELECT basics"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 1,
   "metadata": {
    "tags": []
   },
   "outputs": [
    {
     "name": "stdout",
     "output_type": "stream",
     "text": [
      "Loading spark-stubs, spark-hive\n",
      "Adding Hive conf dir /opt/hive/conf to classpath\n",
      "Creating SparkSession\n"
     ]
    },
    {
     "name": "stderr",
     "output_type": "stream",
     "text": [
      "SLF4J: No SLF4J providers were found.\n",
      "SLF4J: Defaulting to no-operation (NOP) logger implementation\n",
      "SLF4J: See https://www.slf4j.org/codes.html#noProviders for further details.\n"
     ]
    },
    {
     "data": {
      "text/html": [
       "<a target=\"_blank\" href=\"http://jupyter:4041\">Spark UI</a>"
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/plain": [
       "\u001b[32mimport \u001b[39m\u001b[36m$ivy.$                                  \n",
       "\n",
       "\u001b[39m\n",
       "\u001b[32mimport \u001b[39m\u001b[36morg.apache.log4j.{Level, Logger}\n",
       "\u001b[39m\n",
       "\u001b[32mimport \u001b[39m\u001b[36morg.apache.spark._\n",
       "\u001b[39m\n",
       "\u001b[32mimport \u001b[39m\u001b[36morg.apache.spark.sql._\n",
       "\u001b[39m\n",
       "\u001b[32mimport \u001b[39m\u001b[36morg.apache.spark.sql.functions._\n",
       "\n",
       "\u001b[39m\n",
       "\u001b[36mspark\u001b[39m: \u001b[32mSparkSession\u001b[39m = org.apache.spark.sql.SparkSession@1577ad41"
      ]
     },
     "execution_count": 1,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import $ivy.`org.apache.spark::spark-sql:3.4.0`\n",
    "\n",
    "import org.apache.log4j.{Level, Logger}\n",
    "Logger.getLogger(\"org\").setLevel(Level.OFF)\n",
    "\n",
    "import org.apache.spark._\n",
    "import org.apache.spark.sql._\n",
    "import org.apache.spark.sql.functions._\n",
    "\n",
    "val spark = {\n",
    "    NotebookSparkSession.builder()\n",
    "    .progress(false)\n",
    "    .appName(\"app00\")\n",
    "    // .master(\"spark://192.168.31.31:7077\")\n",
    "    .master(\"local[*]\")\n",
    "    .config(\"spark.sql.warehouse.dir\", \n",
    "            \"hdfs://192.168.31.31:9000/user/hive/warehouse\") \n",
    "    .config(\"spark.cores.max\", \"4\") \n",
    "    .config(\"spark.executor.instances\", \"1\") \n",
    "    .config(\"spark.executor.cores\", \"2\") \n",
    "    .config(\"spark.executor.memory\", \"10g\") \n",
    "    .config(\"spark.shuffle.service.enabled\", \"false\") \n",
    "    .config(\"spark.dynamicAllocation.enabled\", \"false\") \n",
    "    .config(\"spark.sql.catalogImplementation\", \"hive\")\n",
    "    .config(\"spark.sql.repl.eagerEval.enabled\", \"true\")\n",
    "    .config(\"spark.driver.allowMultipleContexts\", \"true\")\n",
    "    .getOrCreate()\n",
    "}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 2,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "\u001b[32mimport \u001b[39m\u001b[36mspark.implicits._\n",
       "\u001b[39m\n",
       "defined \u001b[32mfunction\u001b[39m \u001b[36msc\u001b[39m\n",
       "\u001b[36mhiveCxt\u001b[39m: \u001b[32msql\u001b[39m.\u001b[32mhive\u001b[39m.\u001b[32mHiveContext\u001b[39m = org.apache.spark.sql.hive.HiveContext@1d5c79dd"
      ]
     },
     "execution_count": 2,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "import spark.implicits._\n",
    "def sc = spark.sparkContext\n",
    "val hiveCxt = new org.apache.spark.sql.hive.HiveContext(sc)"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 3,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/plain": [
       "defined \u001b[32mclass\u001b[39m \u001b[36mRichDF\u001b[39m"
      ]
     },
     "execution_count": 3,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "// Credit to Aivean\n",
    "implicit class RichDF(val ds:DataFrame) {\n",
    "    def showHTML(limit: Int = 50, truncate: Int = 100) = {\n",
    "        import xml.Utility.escape\n",
    "        val data = ds.take(limit)\n",
    "        val header = ds.schema.fieldNames.toSeq        \n",
    "        val rows: Seq[Seq[String]] = data.map { row =>\n",
    "          row.toSeq.map {cell =>\n",
    "            val str = cell match {\n",
    "              case null => \"null\"\n",
    "              case binary: Array[Byte] => binary.map(\"%02X\".format(_)).mkString(\"[\", \" \", \"]\")\n",
    "              case array: Array[_] => array.mkString(\"[\", \", \", \"]\")\n",
    "              case seq: Seq[_] => seq.mkString(\"[\", \", \", \"]\")\n",
    "              case _ => cell.toString\n",
    "            }\n",
    "            if (truncate > 0 && str.length > truncate) {\n",
    "              // do not show ellipses for strings shorter than 4 characters.\n",
    "              if (truncate < 4) str.substring(0, truncate)\n",
    "              else str.substring(0, truncate - 3) + \"...\"\n",
    "            } else {\n",
    "              str\n",
    "            }\n",
    "          }: Seq[String]\n",
    "        }\n",
    "    publish.html(s\"\"\" <table>\n",
    "                <tr>\n",
    "                 ${header.map(h => s\"<th>${escape(h)}</th>\").mkString}\n",
    "                </tr>\n",
    "                ${rows.map {row =>\n",
    "                  s\"<tr>${row.map{c => s\"<td>${escape(c)}</td>\" }.mkString}</tr>\"\n",
    "                }.mkString}\n",
    "            </table>\n",
    "        \"\"\")\n",
    "    }\n",
    "}"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 4,
   "metadata": {
    "tags": []
   },
   "outputs": [
    {
     "data": {
      "text/plain": [
       "\u001b[36mworld\u001b[39m: \u001b[32mDataFrame\u001b[39m = [name: string, continent: string ... 6 more fields]"
      ]
     },
     "execution_count": 4,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "val world = hiveCxt.table(\"sqlzoo.world\")"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 1. Introducing the `world` table of countries\n",
    "\n",
    "The example uses a WHERE clause to show the population of \"France\". Note that strings (pieces of text that are data) should be in \"single quotes\";\n",
    "\n",
    "**Modify it to show the population of Germany**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 5,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       " <table>\n",
       "                <tr>\n",
       "                 <th>population</th>\n",
       "                </tr>\n",
       "                <tr><td>8.31493E7</td></tr>\n",
       "            </table>\n",
       "        "
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "(world.filter($\"name\" === \"Germany\")\n",
    " .select(\"population\")\n",
    " .showHTML())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 2. Scandinavia\n",
    "\n",
    "Checking a list The word **IN** allows us to check if an item is in a list. The example shows the name and population for the countries \"Brazil\", \"Russia\", \"India\" and \"China\".\n",
    "\n",
    "**Show the name and the population for \"Sweden\", \"Norway\" and \"Denmark\".**"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 6,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       " <table>\n",
       "                <tr>\n",
       "                 <th>name</th><th>population</th>\n",
       "                </tr>\n",
       "                <tr><td>Denmark</td><td>5822763.0</td></tr><tr><td>Norway</td><td>5367580.0</td></tr><tr><td>Sweden</td><td>1.0338368E7</td></tr>\n",
       "            </table>\n",
       "        "
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    },
    {
     "data": {
      "text/plain": [
       "\u001b[36mlistVal\u001b[39m: \u001b[32mSeq\u001b[39m[\u001b[32mString\u001b[39m] = \u001b[33mList\u001b[39m(\u001b[32m\"Sweden\"\u001b[39m, \u001b[32m\"Norway\"\u001b[39m, \u001b[32m\"Denmark\"\u001b[39m)"
      ]
     },
     "execution_count": 6,
     "metadata": {},
     "output_type": "execute_result"
    }
   ],
   "source": [
    "val listVal = Seq(\"Sweden\", \"Norway\", \"Denmark\")\n",
    "(world.filter($\"name\".isin(listVal: _*))\n",
    " .select($\"name\", $\"population\")\n",
    " .showHTML())"
   ]
  },
  {
   "cell_type": "markdown",
   "metadata": {},
   "source": [
    "## 3. Just the right size\n",
    "\n",
    "Which countries are not too small and not too big? `BETWEEN` allows range checking (range specified is inclusive of boundary values). The example below shows countries with an area of 250,000-300,000 sq. km. Modify it to show the country and the area for countries with an area between 200,000 and 250,000."
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 7,
   "metadata": {},
   "outputs": [
    {
     "data": {
      "text/html": [
       " <table>\n",
       "                <tr>\n",
       "                 <th>name</th><th>area</th>\n",
       "                </tr>\n",
       "                <tr><td>Belarus</td><td>207600.0</td></tr><tr><td>Ghana</td><td>238533.0</td></tr><tr><td>Guinea</td><td>245857.0</td></tr><tr><td>Guyana</td><td>214969.0</td></tr><tr><td>Laos</td><td>236800.0</td></tr><tr><td>Romania</td><td>238391.0</td></tr><tr><td>Uganda</td><td>241550.0</td></tr><tr><td>United Kingdom</td><td>242900.0</td></tr>\n",
       "            </table>\n",
       "        "
      ]
     },
     "metadata": {},
     "output_type": "display_data"
    }
   ],
   "source": [
    "(world.filter($\"area\".between(200000, 250000))\n",
    " .select($\"name\", $\"area\")\n",
    " .showHTML())"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": 8,
   "metadata": {},
   "outputs": [],
   "source": [
    "spark.stop()"
   ]
  },
  {
   "cell_type": "code",
   "execution_count": null,
   "metadata": {},
   "outputs": [],
   "source": []
  }
 ],
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